Apparatus for measuring pressures



C. F. SMITH APPARATUS FOR MEASURING PRESSURES May 22, 1928.

Filed June 5, 1924 2 Sheets-$heet l May 22, 1928. 1,670,670 I C. F. SMITH APPARATUS FOR MEASURING PRESSURES Filed June 5, 1924 2 Sheets-Sheet 2 AZU67Z$O r Patented May 22, 1928. p a l 1,670,670

" UNITED *sTATEs PATENT recs. I

CHARLES F. SMITI-IQOF BOSTON, MASSA('JI-IUSE'JE'JJS.

APPARATUS FOR MEASURING PRESSUBES.

Application filed June 5, 1924. Serial No. 718,008.

v This invention relates to apparatus for In the drawings illustrating the preferred measuring the pressure within a flexible conembodiment of the invention, Fig.1 is a plan tainer by an instrument applied to the ex of the improved tire gaugeillustrating the terior thereof, and more particularly to a manner in which the same, is applied to a.

5 tire gaugefor measuring the pressure withmotor vehicle tire; Fig; 2 is a sectional detail 60 in the tire by an instrument applied to'the on line 2-2'of Fig. 3; Fig. 3 is a, sectional exterior of the tire itself. r detailon line 33 of Fig, 2; Fig. dis a plan The object of the invention is to provide of a, portion of the gauge illustrating the novel apparatus ofthe character specified position assumed by thefparts after the tire bywhich the pressure within a flexible conhas been compressed; Fig. 5is a similar view. 65

tainer may be measured in a simple and illustrating theparts before the tire has been highly convenient manner. A further obcompressedgand Figs. 6 and 7 are details in ject of the invention is to provide a novel section taken upon the lines 6.-6'and 7 tire gauge of the character specified which of'Fig; 1. i

has provision for illuminating the gauge to Referring to thedrawings, the improved 70 visibly indicate the registered pressure, and measuring apparatus as illustrated therein which is therefore particularly adapted for isembodied in a tire gauge comprising two use in garages to enable the operator to effijaws 10, 12 for engaging the, exterior of a ciently gauge the inflation of a large numtire in the manner illustrated inFig. 1 and her of tires of the motor vehicles stored one of which jaws is arranged to be movable 75 in th garage, with relation to the other. The jaws 10, 12

To these ends the apparatus is provided are preferably providedwith relatively inwith means for engaging and compressing clined faces a'dapted toeng'age the sidewalls the exterior of a flexible container, the presof the tire. vAs herein shown, the stationary sure within which it is desired to measure, jaw 10 is provided with a bar 13 comprising 80 and also with means for registering the'rea. guide upon which a carrier member let is sistance offered by the container to compres slidably Inountedto be capable of movement sion. Provision is made for indicatin when toward and away from the stationary jaw the container has been compressed a efinite 10. The carrier member 14 isprovided with amount in order that a comparison may be a roller 15 which frictionally engages the S5 obtained between the properly calibrated sides of a slot in thevguide bar 13. The

registered resistance and a predetermined movable jaw 12 may and pre-fera-bly will be pressure represented by said definite comadjustably mounted upon the carrier mempression. I i I I ber l t to be capable of adjustment longi In its preferred form, the invention is tudinally thereof, and is held in its adjusted-'90 embodied in a tire gauge and provision is positions by. the cooperation of a spring; made for adjustably varying the amount of pressed locking dog 16 with one of the teeth the definite compression above referred to, 17 upon the side of' the carrier member lt, and the adjustment is calibrated against as illustrated'in'Figs. 1 and 6.

' known pressures'within tires of the different The jaws 10, 12are arranged to be moved sizes so that the operator may make the adtoward and away from one another by levers justment for a given size of tire and then by 20, v21, pivotally mounted' upon a common compressing a tire of a size corresponding to stud 24. The movement of the carrier memsuch adjustment until the indication is given ber 14: away from the stationary jaw 10 I 1 that the definite compression has taken place, is adjust-ably limited by the cooperation of a he may obtain from the calibrated registered. cam 18 with a stop 19 upon the end of the resistance the pressure within the tire. The guide bar 13. The cam 18 is arranged to be indication that the definite compression has adjustably moved by. a, knurled nut 23 to.

taken place is'preferably obtained by illumipermit the totalextent of move'm entof the nating at such time theresistance registering 1 carrier member to be. adjustably "varied. 10 5.

' mechanism. 1 I 1 v The lever 20 .is pivotally connected tozthe.

These and other features of the invencarrier'member 14 on stud 25 and thelever tion will be hereinafter described and par- 21 is connected to. the stationary, jaazv' 10,:

ticularly pointed out in the claims at the end through a pressure registering mechanism inthis specification. dicated. genera11yas26 and through a lever. no

32 aflixed to the end of the lever 28. The baris arranged to slide in a bracket 34:' on the underside of the lever 21. The pressure cylinder is provided with a piston .33 therein, adapted tobe engaged and actuated by a contact member 38 affixed upon the lever 21, and in-practice the piston may comprise one end of a hollow m'etallic bellows oi known construction, the second end of which is affixed to: the. cylinder 30. j The piston 33 comprising the first end of the bellows is adapted tobc engaged by the; contact member 88, so that upon movement of the lever '21, the contact member 38 engages and moves the piston'33, compressing the air or other fluidwithin the bellows. Provision is made for registering thepressure of the air thus compressed, and for this purpose the cylinder 30 is connected by a connecting pipe 36 to a pressureregistering gauge 40 of any usual or preferred construction andwhich is illustrated as ailixed upon the lever 28, to be carried thereby, so that in the use of the measuring instrument, when the levers 20, 21 are manually moved together to compress the portion of the tire between the jaws 10, 12, the resistance offered by the tire to compressionis transmitted through the levers 20, 28 which are directly connected to the jaws 10,12, to the piston 33 of the bellows within the cylinder 30, and consequently to the pressure gauge 5L0, registering upon the gauge the measure of the resistance oilered by the tire to compression.

v The pressure gauge 40 may and preferably will be calibrated against standard pressures Within tires so as to record this resistance in units of pressure corresponding to the pressure to which a tire is inflated. Provision is ,mad e for illuminating the pressure registering gauge 4.0when themovable carrier member 14 inits movement toward the stationary jaw 10 reachesa predetermined point, and for this purpose an illuminating device comprising, preferably a flash light 50 may anclpreferably will be inountedupon the end of the lever 28 in position to direct itsrays over the face of the gauge. 10. The

1 flash light may be operatively connected through wiring 51' to a contact member 52 comprising a spring pressed yleldableplu ge mounted upo th te a y J 10; The movable carrier member 14 may benro id' d with a Contact ,mem i adapted to engage with the contact member 52 when the Jcarrier member 14 arrives atjthe predetermined point inits movement toward, the. s at enai'yiw 510,;v an e y c plete the circuit to'operate the 'fiash light,

thus illuminating the dial or face of the pressure registering gauge 40. The plunger 52 and contact member 54; constitute a switch. The circuit is completed from the contact member 5,4athroughythe arm 28 back to the casing 50 of the flashlight, the casing 50 being connected in the usual manner to the usual battery (not shown) within the flash.- light casing. The extent of this predetermined movement of the carrier membenll: is arranged to correspond to the proper inflation of a. tire of a given size, and when the carrier member reaches the point in its movement toward the stationary jaw 1O at which the gauge is illuminated, the operator may readily note the pressure registered. on the gauge 40, and by comparing the registeredpressure with that pressure which cor responds to the predetermined movement of the carrier member 14-, he is advised that the tire being gauged is either above, below, or possesses the proper inflation, and also as to the amount of air pressure whichshould be added to or taken from the tire to restore itto a properly inflated condition.

In the preferred embodiment ofthe in-- vention provision is madefor adjustably varying the possible extent of movement of the carrier member 1 1 towardthe station ary jaw, in order that the carrier" member may have a total possible movement from its extreme open position until the lighting circuit is closed between the contact menibers 52, 54, corresponding to different sizes of tires. In practice this is preferably accomplished by means of the cam 18 arranged to cooperate with the stop 19 on the end of the guide bar 13 to limit the outward movement of the carrier member 14. The cam 18 is, as has been stated, operatedby a knurled nut 23.and the apparatus calibrated against known pressures in different sizes of tires so as" to determine different positions of the cam corresponding'to different predetermined amounts of compression in the tires of the different sizes. In order that the operator may conveniently adjust the cam, a scale 29 indicating tiresizes preferably provided upon the top of the knurlednut 23 as indicated in Figs. 1, d, "and 5. In the operation of the apparatus, the operator first adjusts the cam 18 to a position.

in which the carrier member let may have the requisite movement until the lighting circuit is closed corresponding to the proper amount of compression so that thepressure registering gauge may give a reading of the true'pressure within the I tire of that particular size. Then the operator applies the jaws 10, 12 to the tire in the manner illustrated in Fig. 1, adjusting the jaw 12' ends of the levers 20, 21 together until 'the the event that the pressure within the tire is above'or below; the desired amount, he may reduce or increase thepressure in the usual way by manipulation o't thc usual air valve. In the garage the operator may gauge all the tires of a given size with a-single ad 'ustm'ent of the ca m 18,'and then in the event that he desires to gauge tires of difterent sizes, he may adjust the cam to a position corresponding "to the size of the next set ot tires to be gauged.

From the description, thus far, it will be observed that in accordance with the pres ent invention an instrument is'provided for enabling the operator to conveniently and rapidly measure the inflation of motor vehicle tires by an instrument applied to the outside ofthe tire. Thisis particularly useful in garage work where the cars are stored close together and it is only with difiiculty and inconvenience that the operator may apply the ordinary form of pressure gauge to the tire valve. By means of thepresent instrument, the operatormay quickly gauge or test the inflation of the tires'from the front and rear of the vehicies, and the fact that the pressure gauge itself is illuminated assists materially in the convenience-oi? using the instrument at nightor in garages having poor lighting facilities. ferred embodiment of the invention has been illustrated and described, it is to be understood that the invention may be embodied'in other forms within the scope'o'i the following claims. i

I claim i 1. Apparatus of the character described comprising a pair of relatively tmovable members for engaging a flexible container to be tested, means for relatively moving said members to compress a portion of the container, pressure registering means 00- I operating with said members to be actuated by the resistance to movement of said members offered by'said flexible container, and means for illuminating said pressure registering means controlled by said movable members and operated thereby when a predetermined point is reached in the relative movement of said members toward each other.

2. Apparatus of the character described comprising means applicable to the exterior of a flexible container for compressing a portion of the same, pressure registering means co-operating with said members to be lVhile the pro-" by said; movable members and operated thereby when predetermined pointjh'as been reached in the compressionotsaid con,- tainer. I l

3. Apparatusof the characterdescribed comprising means applicable to the-exterior of" a flexible container for compressinga portion]- of the same, pressure registering means operatively connected therewith to vbe actuatedithereby when the resistance of the container reaches a predetermined point, and means co-operating with said compressing means for indicating a predetermined coin-I pressionjin said container;

djA pressure gauge fortires'comprising jaws capable of engaging the-sidewalls of a, tire mounted on a" rim, means for .moving said jaws toward each other to compress said tire. and means co-operating with said jaw-moving means and rendered efl'efctive by the latter to indicate a predetermined compression in said tire. v i V 5. A pressure gauge for tires comprising a pair of relatively movable tire engagihg members, means for relatively moving said.

members to compress a portion of a the between them, means actuated by said members for, registering the resistance offeredby the tire to compression, an electric lam'p adapted to illuminate said registering means and electrical connections between the lamp and compressing members and actuated by the latter for lighting the lamp at a predetermined point in the relative movement of said compressing members. G. A; pressure gaugeior tires comprising means applicable to the exterior of the tire for compressinga portion of the same,- in cluding a tireengaging member having a guide bar, a movable tire engaging member, a; c. rriermeinber arranged to slide upon said guide bar and upon which said-movable the engaging member i's mounted,-flevers for moving the carrier member toward and away from the stationary tire engaging member, and a pressure registering device cooperating with said tire-engaging members to be actuated thereby for registering the resistance offered to compression of said tire by said members. 7. A pressure gauge for tires comprising means applicable to the eirterior of the tire for compressing a portion of the same, including a tire engaging member having a guide bar connected therewith, a movable tire engaging member, a: carrier member arranged toslide upon said guide member, and upon which said tire engagingmember is mounted, levers for moving the carrier member toward the first-mentioned tire engaging member, a pressure registering device co-operating with sand tire-engaglng members to be actuated thereby for registering the resistance offered to compression by the tire, and means for illuminating the pressure, registering device renderedv operative by a predetermined movement of said carrier member. 1

8. A pressure gauge for tires comprising means applicable to the exterior of the tire for compressing a portion of the same, including a tire engagingmember, having a guide bar connected therewith, a second tire engaging member, a carrier member arranged to slide upon said guide member and upon which the second tire engaging member is mounted, means for moving the carrier member toward the first the engaging member to effect .a compression oi": the tire, a pressure registering device co-operating with said. tire-engaging members to'be actuated thereby for registering the resistance offered by the tire to compression, means for illuminating the pressure registering device upon predetermined movement of the carrier member, and means for adjustably limiting the possible extent of movement of the carrier member. I

9. A pressure gauge for tires comprising means applicable to the exterior of the tire for compressing a portion of the same, pressure registering means connected therewith to be actuated thereby for registering the resistance of the tire to compression, and means controlled by'said compressing means for illuminating the pressure registering means when the tire has been compressed a predetermined amount, and means for adjusting the point at which such illumination occurs. I

10. In an apparatus of the character described, jaws for engaging a yielding container, one of which is movable toward the other, levers carrying said jaws, a gauge carried by said levers, an hydraulic cylinder connected with said gauge and responsive to pressure between said jaws, and means for indicating a predetermined movement of said movable jaws to thereby obtain a comparison of a predetermined pressure represented by said movement with the pressure in the container. a

11. In an apparatus of the character described, jaws' for engaging a yielding container, one of which is movable toward the other, levers carrying said jayvs, a gauge carried by said levers, an hydraulic cylinder connected with said gauge and responsive to pressure between said jaws, an electric light for illuminating said gauge, and a circuit controller for said electric light op erated by said movable jaw. V I i 12. In an apparatus of the character described, jaws for engaging a yielding eontainer, 'means for moving one-0t said jaws toward the other to indicate pressure in said container, and means co-operating with said movable jaw for indicating when the movable jaw has been moved a predetermined distance to thereby obtain a comparison of a predetermined pressure represented by said movement with the pressure in the container.

13. Apparatus of the character described comprising two relatively movable members for engaging the exterior of a flexible con tainer and compressing the same, supporting members upon which the said engaging members are mounted, registering means cooperating with said members to be actuated thereby for registering the resistance olfered by the container to compression, means cooperating with said movable members for indicating a predetermined compression in the container, vand means for adjusting the position of one of said engaging members upon its supporting member.

- In testimony whereof, I have signed my name to this specification.

' CHARLES F. SMITH 

